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-rw-r--r--drivers/usb/roles/intel-xhci-usb-role-switch.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/usb/roles/intel-xhci-usb-role-switch.c b/drivers/usb/roles/intel-xhci-usb-role-switch.c
new file mode 100644
index 000000000..5c96e929a
--- /dev/null
+++ b/drivers/usb/roles/intel-xhci-usb-role-switch.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Intel XHCI (Cherry Trail, Broxton and others) USB OTG role switch driver
+ *
+ * Copyright (c) 2016-2017 Hans de Goede <hdegoede@redhat.com>
+ *
+ * Loosely based on android x86 kernel code which is:
+ *
+ * Copyright (C) 2014 Intel Corp.
+ *
+ * Author: Wu, Hao
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/usb/role.h>
+
+/* register definition */
+#define DUAL_ROLE_CFG0 0x68
+#define SW_VBUS_VALID BIT(24)
+#define SW_IDPIN_EN BIT(21)
+#define SW_IDPIN BIT(20)
+#define SW_SWITCH_EN BIT(16)
+
+#define DRD_CONFIG_DYNAMIC 0
+#define DRD_CONFIG_STATIC_HOST 1
+#define DRD_CONFIG_STATIC_DEVICE 2
+#define DRD_CONFIG_MASK 3
+
+#define DUAL_ROLE_CFG1 0x6c
+#define HOST_MODE BIT(29)
+
+#define DUAL_ROLE_CFG1_POLL_TIMEOUT 1000
+
+#define DRV_NAME "intel_xhci_usb_sw"
+
+struct intel_xhci_usb_data {
+ struct device *dev;
+ struct usb_role_switch *role_sw;
+ void __iomem *base;
+ bool enable_sw_switch;
+};
+
+static const struct software_node intel_xhci_usb_node = {
+ "intel-xhci-usb-sw",
+};
+
+static int intel_xhci_usb_set_role(struct usb_role_switch *sw,
+ enum usb_role role)
+{
+ struct intel_xhci_usb_data *data = usb_role_switch_get_drvdata(sw);
+ unsigned long timeout;
+ acpi_status status;
+ u32 glk, val;
+ u32 drd_config = DRD_CONFIG_DYNAMIC;
+
+ /*
+ * On many CHT devices ACPI event (_AEI) handlers read / modify /
+ * write the cfg0 register, just like we do. Take the ACPI lock
+ * to avoid us racing with the AML code.
+ */
+ status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
+ if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
+ dev_err(data->dev, "Error could not acquire lock\n");
+ return -EIO;
+ }
+
+ pm_runtime_get_sync(data->dev);
+
+ /*
+ * Set idpin value as requested.
+ * Since some devices rely on firmware setting DRD_CONFIG and
+ * SW_SWITCH_EN bits to be zero for role switch,
+ * do not set these bits for those devices.
+ */
+ val = readl(data->base + DUAL_ROLE_CFG0);
+ switch (role) {
+ case USB_ROLE_NONE:
+ val |= SW_IDPIN;
+ val &= ~SW_VBUS_VALID;
+ drd_config = DRD_CONFIG_DYNAMIC;
+ break;
+ case USB_ROLE_HOST:
+ val &= ~SW_IDPIN;
+ val &= ~SW_VBUS_VALID;
+ drd_config = DRD_CONFIG_STATIC_HOST;
+ break;
+ case USB_ROLE_DEVICE:
+ val |= SW_IDPIN;
+ val |= SW_VBUS_VALID;
+ drd_config = DRD_CONFIG_STATIC_DEVICE;
+ break;
+ }
+ val |= SW_IDPIN_EN;
+ if (data->enable_sw_switch) {
+ val &= ~DRD_CONFIG_MASK;
+ val |= SW_SWITCH_EN | drd_config;
+ }
+ writel(val, data->base + DUAL_ROLE_CFG0);
+
+ acpi_release_global_lock(glk);
+
+ /* In most case it takes about 600ms to finish mode switching */
+ timeout = jiffies + msecs_to_jiffies(DUAL_ROLE_CFG1_POLL_TIMEOUT);
+
+ /* Polling on CFG1 register to confirm mode switch.*/
+ do {
+ val = readl(data->base + DUAL_ROLE_CFG1);
+ if (!!(val & HOST_MODE) == (role == USB_ROLE_HOST)) {
+ pm_runtime_put(data->dev);
+ return 0;
+ }
+
+ /* Interval for polling is set to about 5 - 10 ms */
+ usleep_range(5000, 10000);
+ } while (time_before(jiffies, timeout));
+
+ pm_runtime_put(data->dev);
+
+ dev_warn(data->dev, "Timeout waiting for role-switch\n");
+ return -ETIMEDOUT;
+}
+
+static enum usb_role intel_xhci_usb_get_role(struct usb_role_switch *sw)
+{
+ struct intel_xhci_usb_data *data = usb_role_switch_get_drvdata(sw);
+ enum usb_role role;
+ u32 val;
+
+ pm_runtime_get_sync(data->dev);
+ val = readl(data->base + DUAL_ROLE_CFG0);
+ pm_runtime_put(data->dev);
+
+ if (!(val & SW_IDPIN))
+ role = USB_ROLE_HOST;
+ else if (val & SW_VBUS_VALID)
+ role = USB_ROLE_DEVICE;
+ else
+ role = USB_ROLE_NONE;
+
+ return role;
+}
+
+static int intel_xhci_usb_probe(struct platform_device *pdev)
+{
+ struct usb_role_switch_desc sw_desc = { };
+ struct device *dev = &pdev->dev;
+ struct intel_xhci_usb_data *data;
+ struct resource *res;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -EINVAL;
+ data->base = devm_ioremap(dev, res->start, resource_size(res));
+ if (!data->base)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, data);
+
+ ret = software_node_register(&intel_xhci_usb_node);
+ if (ret)
+ return ret;
+
+ sw_desc.set = intel_xhci_usb_set_role,
+ sw_desc.get = intel_xhci_usb_get_role,
+ sw_desc.allow_userspace_control = true,
+ sw_desc.fwnode = software_node_fwnode(&intel_xhci_usb_node);
+ sw_desc.driver_data = data;
+
+ data->dev = dev;
+ data->enable_sw_switch = !device_property_read_bool(dev,
+ "sw_switch_disable");
+
+ data->role_sw = usb_role_switch_register(dev, &sw_desc);
+ if (IS_ERR(data->role_sw)) {
+ fwnode_handle_put(sw_desc.fwnode);
+ return PTR_ERR(data->role_sw);
+ }
+
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ return 0;
+}
+
+static int intel_xhci_usb_remove(struct platform_device *pdev)
+{
+ struct intel_xhci_usb_data *data = platform_get_drvdata(pdev);
+
+ pm_runtime_disable(&pdev->dev);
+
+ usb_role_switch_unregister(data->role_sw);
+ fwnode_handle_put(software_node_fwnode(&intel_xhci_usb_node));
+
+ return 0;
+}
+
+static const struct platform_device_id intel_xhci_usb_table[] = {
+ { .name = DRV_NAME },
+ {}
+};
+MODULE_DEVICE_TABLE(platform, intel_xhci_usb_table);
+
+static struct platform_driver intel_xhci_usb_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ },
+ .id_table = intel_xhci_usb_table,
+ .probe = intel_xhci_usb_probe,
+ .remove = intel_xhci_usb_remove,
+};
+
+module_platform_driver(intel_xhci_usb_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_DESCRIPTION("Intel XHCI USB role switch driver");
+MODULE_LICENSE("GPL");